The best items to use for the Parametric Transformer Gadget in Genshin Impact are NPC items that you can purchase large quantities of weekly.

Basically this gadget gives players a way to transform their excess materials into something useful.

Unlock Parametric Transformer Gadget

Complete the Tianqiu Treasure Trail Quest to unlock the Parametric Transformer.

The quest can be accepted from Lan (shes next to the Adventurer’s Guild NPC in Liyue)

  1. Defeat some Hilichurls.
  2. Follow the Treasure Map to Danyu Ruins (x marks the spot).
  3. Dig up the 3 Treasure Chests.
  4. Speak to Lan again.

Transmutation

  1. Place down the Parametric Transformer.
  2. Add 150 quality worth of items.
    – 1-Star Items = 1 Point
    – 2-Star Items = 2 Points
    – 3-Star and 4-Star Items = 4 Points
  3. Initiate transmutation (this will consume the inputted items).
  4. Use Elemental Attacks to charge the transformer (Fischl’s Oz is great for this).
  5. Rewards include Mora, Character EXP Materials (eg. Hero’s Wit), Talent Books, Enhancement Ore, Character Level Up Materials (the coloured crystals) and Weapon Ascension Materials.
  6. The Parametric Transformer has a cool down of 7 days before it can be used again.